A. Field of the Invention
The invention relates to an output apparatus for data, in particular audio data, digitally stored on a data carrier, comprising a reading unit for reading the data from the data carrier as analogue signals, further comprising a data converter unit for data processing and an output unit for the output of processed data.
B. Description of the Related Art
Such an apparatus is known from DE-U 295 00376. For the output of digitally stored data on a data carrier an optical reading unit for entering the data is provided for this device, having an optical reading head, which is to be passed over the data carrier as a so-called manual scanner. After processing the entered data in a data converter, a sound sequence can be reproduced as audio data, for example in a loudspeaker, serving as the output device.
Although the apparatus according to the generic clause is, in principle, functional, it appears to be in need of improvement in many respects for a high-quality reproduction of digitally stored data.
Another such apparatus is known from EP 0 773 511. For the output of digitally stored data on a data carrier an optical reading unit having an image sensor is provided for this device for entering the data. An initial processing is performed on the lowermost level 1 for an image of the image sensor, the first result being analysed for data blocks contained therein on level 2 thereabove. The second result is combined into macro blocks on level 3 thereabove, being subsequently combined in partial data files on level 4, which are then grouped into data files on level 5 and which are placed at the disposal of the overriding application.
This apparatus according to the generic clause as well is, in principle, functional. It is even possible to attain high-quality reproduction, if the process applied to the levels is appropriately designed. However, the apparatus requires a relatively long time from recording the images of the image sensor until the data output, for example as a sound sequence, due to the stepwise processing of the data contained in surface units, which is considered a drawback by a user of the apparatus. Moreover, the use of image sensors impairs an economical and dimensionally small realisation of a particularly high data density of data digitally stored on a data carrier.
It is therefore the object of the invention to particularly so further develop a device of the type set out in the opening paragraph that, in particular, in the event of high density of data to be reproduced a comparatively fast and, to a large extent, error-free data processing is brought about.
This object is attained by an apparatus according to the main claim while advantageous embodiments are set out in the subsidiary claims.
Due to the fact that a start block detector unit and a control data storage unit are provided, by means of which stored control data can be read and stored in a start block of the data carrier, subsequent data processing can be systematically controlled by preset parameters contained in the control data. According to the invention data reconstruction elements are provided for this purpose, which, supplied by associated control data influence the processing of the data to be reproduced in such a manner that even large amounts of data can be processed fast and without error.
In working examples, the control data storage unit as well as the data converter unit comprise as storage and output elements or as data reconstruction elements associated therewith in each case alternatively and/or cumulatively a binary threshold value indicator with an associated binary reconstruction element for the conversion into binary data of analogue signals according to a predetermined threshold value, further comprising a twist correction indicator, having a twist correction element associated therewith in order to compensate for a twisting of the data carrier deviating in relation to the desired direction, further comprising a grid size signal means with an associated texture reconstruction element for the reduction to a data set corresponding to the actual grid size of the data carrier, so that in the event of a coarser grid size of the data carrier in relation to the resolution capability of the reading unit entering processes are accelerated, further comprising a data format means with an associated data processing element for decompression or, respectively, decoding as well as for error correction with regard to a specific data format as well as comprising a level control value signalling means with an associated digital analogue converter for the correct output conversion into reproduction signals.
The reading unit is preferably designed for optically reading the data. For this purpose embodiments are provided, which include structural elements, pivotal or slidable in relation to a stationary data carrier, by means of which the data can preferably be read line by line.